This blog post by Martha Peterson based on a NYT article she links to raises some interesting points for me. I've had some back & hip issues for a while, and yoga did seem to aggravate them, although I can't blame the problems on yoga. I don't know what brought them on. I've gotten the most relief and improvement from somatic exercises, like the ones that Peterson teaches, which are based on Thomas Hanna and Feldenkrais. These are very gentle movements and not done to a beat. I'm continuing and expanding my experiments in this area, and I will report more at a later point.
I must say that sometimes vinyasa yoga class seems like fancy calisthenics to me. I've now slowed down on my own--so what if I miss a chataranga? I also try to feel what I'm doing. And, yes, when upside down or twisted this way or that, I do see others around me who are twisted into shapes that I then aspire to, almost always unsuccessfully. So, yes, I plead guilty to competitiveness, and I will try to keep in mind that I should not try to compete. Most teachers are good at stating stating that we should "listen to our own body", etc., but it's a hard lesson for most. A number of participants and yoga teachers (at least at our studio) are intense athletes as well.
P.S. I have now read the complete original article. It does provide food for thought, but as 1HP pointed out, almost any physical endeavor, if not performed properly, or if performed indiscriminately, can cause problems. She also noted our tendency as Americans to push to extremes. Points well taken. Again, my new emphasis is on mindfulness of movement.